Compatible with pytest-playwright 0.6.2

[maartenbreddels]

Because we pin playwright, we use an old pytest-playwright:

...
Collecting pytest-playwright (from pytest-ipywidgets==1.42.0->pytest-ipywidgets==1.42.0)
  Downloading pytest_playwright-0.5.2-py3-none-any.whl.metadata (1.5 kB)
...

However, the latest version (0.6.2) is not compatible with out pytest-ipywidgets library.

[maartenbreddels]

It did not seem that pinning playwright was the cause of us not upgrading, rather the Python version, since newer versions of pytest-playwright do not support Python 3.8, which is the version we use for integration testing. See https://github.com/microsoft/playwright-pytest/blob/v0.6.2/pytest-playwright/pyproject.toml and https://github.com/microsoft/playwright-pytest/blob/v0.6.2/pytest-playwright/pyproject.toml